Synopsys, Inc.
Bit-level learning for word-level constraint solving

Abstract:

Techniques and systems for solving a set of constraints are described. Binary decision diagram (BDD) learning can be applied to a proper subset of the first set of constraints to obtain a set of bit-level invariants. The set of bit-level invariants can then be used for solving the set of constraints. The set of bit-level invariants can include (1) forbidden invariants, (2) conditional invariants, and/or (3) bit-level invariants that are determined by applying BDD learning to a conjunction of constraints and range expressions. If multiple implied constraints have a common right-hand-side (RHS) expression, then BDD learning can be applied to the common RHS expression only once.